closes https://github.com/NodeBB/NodeBB/issues/5494

templates/header.tpl

@@ -7,13 +7,6 @@
 	<!-- IF bootswatchCSS --><link id="bootswatchCSS" href="{bootswatchCSS}" rel="stylesheet" media="screen"><!-- ENDIF bootswatchCSS -->
 	<!-- BEGIN linkTags -->{function.buildLinkTag}<!-- END linkTags -->
 
-	<!--[if lt IE 9]>
-  		<script src="//cdnjs.cloudflare.com/ajax/libs/es5-shim/2.3.0/es5-shim.min.js"></script>
-  		<script src="//cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7/html5shiv.min.js"></script>
-  		<script src="//cdnjs.cloudflare.com/ajax/libs/respond.js/1.4.2/respond.min.js"></script>
-  		<script>__lt_ie_9__ = 1;</script>
-	<![endif]-->
-
 	<script>
 		var RELATIVE_PATH = "{relative_path}";
 		var config = JSON.parse('{{configJSON}}');